Field of the Invention
The present invention relates in general to the fields of image processing and computer vision, in particular to an image composition evaluating apparatus, an information processing apparatus and methods thereof.
Description of the Related Art
The quality of an image is determined not only by its content, but also by its composition. Take photographic images as an example. Many pictures include views people want to shoot, yet they still look unattractive due to various composition problems. Since composition is too complicated for beginners, most beginners need an intelligent camera to help them to get better pictures.
To deal with this situation, Fujifilm has proposed an imaging apparatus with Human Composition Judgement, which can judge whether the composition is appropriate or not based on human extraction results. FIG. 1 and FIGS. 2-3 show a schematic view and flowcharts of Fujifilm's Human Composition Judgement method, respectively. As shown in FIG. 2, first, at step 210, human objects are extracted based on face detection in an image (the human object extraction result is shown by a solid rectangle in FIG. 1). Next, at step 220, non-human objects are extracted based on special object detection in regions except for the human object extraction region of the image (the non-human object extraction results are shown by polygons in FIG. 1). Finally, at step 230, arrangement balance is evaluated based on whether gravity centers of objects are within a predetermined region of the image. FIG. 3 gives a more detailed flowchart of the arrangement balance evaluation step. As shown in FIG. 3, at steps 310 and 320, the gravity center of each human object and that of each non-human object are calculated, respectively; then, at step 340, judgement is made as to whether the gravity center is within a predetermined region of the image or not. Meanwhile, at step 330, the gravity center of all human and non-human objects is calculated based on results of steps 310 and 320; and then at step 350, judgement is made as to whether the gravity center is far from a center region of the image or not. Finally, at step 360, evaluation is made as to whether the arrangement balance is appropriate or not based on results of steps 340 and 350. In the example shown in FIG. 1, the cross inside the solid rectangle indicates the gravity center of the extracted human object, the crosses inside the polygons indicate the gravity centers of the extracted non-human objects, cross A indicates the gravity center of all human and non-human extracted objects, and cross B indicates the image center. As a result, it is evaluated that the composition of the image shown in FIG. 1 is not good (i.e., gravity center A is low), and thus it is proposed that screen may be zoomed to a position shown by a dashed rectangle in FIG. 1 so that gravity center A is not far from image center B.
However, the above Human Composition Judgement method has many limits.
First, such a method can only deal with pictures with detected human faces. This means that other pictures, such as landscape pictures without special object (see FIG. 25C), object pictures without human (see FIGS. 25D-25E) and even human backside pictures without face (see FIG. 25B), cannot be evaluated at all.
Second, such a method can only help to make a human object in a center region of an image, which is not enough for a good composition. For example, because this method does not care about the scale of a human object, the human object may not be outstanding (see FIG. 25B); because this method does not care about the relationship between a human object and a non-human object, the human position may be uncomfortable (see FIG. 25A); because this method does not care about the background environment, unreasonable composition may be caused by disproportional background (see FIG. 25D) etc.
Therefore, it is desired that a new image composition evaluating apparatus and a method thereof, which are capable of evaluating more kinds of images and/or more kinds of composition problems, can be provided.